Physical and Chemical Papers. 79 



and substitute for it a modern series system. Such a system 

 was finally completed and formally opened Friday night, 

 October 21, 1914. Eight poles per block were installed, each 

 carrying four lamp brackets. The poles are made of three 

 different sizes of seamless steel tubing, welded together, and 

 fitted with ornamental collars, base, brackets and cross-arms. 

 They are set six feet in the ground and are surrounded by 

 concrete 2 ft. by l.V ft., in section, with the 2-foot side parallel 

 to the curb. This heavy base was necessary, as the poles were 

 also used to support the trolley wires for the street-railway 

 system. In return for the privilege of attaching the trolley 

 wires to these poles, the street-car company assisted in the 

 erection of the poles. Fourteen-inch inverted balls are used, 

 with their centers 13 ft. 6 in. above the sidewalk grade. A 

 large number of different makes were tested to secure the 

 best one available, considering cost, absorption of light, 

 strength, and hiding of the filament of the lamp. The Carrara 

 (Dense) globe, made by the Glieson Tiebout Glass Company, 

 of Brooklyn, was selected as meeting best all the conditions. 

 Its apparent absorption was approximately 15 per cent, its 

 weight 5} pounds, and it almost completely hid the lamp, thus 

 giving out a beautiful soft glow. We believe it will take a 

 severe hail storm to injure these globes, since they are un- 

 usually heavy for the amount of light absorbed. 



Three lamps are switched off at eleven o'clock, while the 

 one over the street is operated all night. No moonlight 

 schedule is followed, the lamps being operated every night. 



The three smaller ones are the standard 80 c. p. nitrogen- 

 filled series tungsten, using approximately 56 watts, and the 

 larger one is a special 100-watt, 140 c. p. lamp of the same 

 type. These lamps cost about 88 cents and $1, respectively. 

 The wires are carried overhead in two series circuits, using 

 No. 8 weatherproof wire. This was furnished and installed 

 by the electric-light company. The wires inside the pole are 

 10,000-volt No. 6 solid standard wire, and enter the pole 

 through moisture-proof bushings. One hundred and seventy- 

 three poles were installed at an average cost of $81 per pole. 

 This was paid by a tax on adjacent property in a similar 

 manner to a paving tax. The city pays for the electric cur- 

 rent and maintenance of the system. The electric company 

 made the verj^ moderate rate of $14 per pole per year for the 



